Patent GB-160943-A (GB)
Title: Improvements in or relating to automatic stop mechanism for textile machines
IPC: D04B35/10
Filed: 1919-12-31
Abstract: 160,943. Farrington, R., and Sidebotham, F. Dec. 31, 1919. Stop-motions, warp. -Relates to electrical stop-mechanism of the type in which feelers rest upon the yarn or upon the fabric and are thus held out of action during normal running. The invention is described in connection with a bearded needle loop - wheel knitting- machine for producing fleecy fabric, but is stated to be applicable to other types of knitting machinery and to other machines such as braiding-machines, wirecovering machines, and to the warps in smallware looms. The feelers are lightly constructed to overcome a difficulty experienced in starting-up multi - feed machines provided with heavy mechanically-operated feelers which are liable to drop into machine-stopping position while the machine is standing. The feelers when operative complete a low voltage circuit, sparking at the contacts being thus minimized. This circuit, when closed, operates a switch which closes a higher voltage machine-stopping circuit. The stopping and starting lever 25 carries a tooth 28 engaged by the short arm 30 of a detent 29 while the machine is running. The long arm 31 reaches under a stud 32 projecting from a collar 33 on a vertical spindle 34 which carries a feeler 35 bearing on the fabric. When a fault develops the feeler is engaged thereby rotating the spindle 34 and releasing the detent 29 and lever 25. The above described mechanism is adapted for use with the electrically operated stop-motion described below by lengthening the stud 32 and attaching the end by a lost-motion connection such as a chain 103 to the core 102 of an electromagnet. The lost motion allows the core 102 to move and acquire a little momentum when energized which assists the operation of the studs 32. The feelers- 42, Figs. 7 and 8, for acting on the breakage of yarn consist each of a light wire one end of which is bent round to form or enclose an eye 46 while the other is coiled several times at 43 to take a loose bearing on a stud 41 carried on a support 37, a number of the supports being adjustably mounted on an horizontal bar. The end 47 of therod 43 projects beyond the stud 41 and carries a contact piece 48 having contact points 50 which are situated so as to bridge two spring contacts 51 when the feeler 42 is in the position shown in dotted lines. Other forms of contacts such as mercury cups could be used. The parts are enclosed in a casing 55 through a slot 56 in which the feeler wire projects. The support 37 also carries a wire yarn guide 58 which is held in position by a screw 59 and is intended to direct the yarn in its path into and out of the feeler guide eye 46. The contacts 51 of each feeler 42 are connected in series to an indicator of known construction bearing an inscription plate which becomes visible when the corresponding contacts 51 are bridged by the fall of the feeler 42, and the indicators may be housed all together in a single casing. The indicators and the corresponding feelers &c. are connected in parallel to a low voltage source of current and to an electromagnet 69 and two contacts 70, 71 of a four-pole rotary switch 72 carrying a bar 77. Tension springs 79, 80 are attached to the bar 77 and to a block 78 in such a manner that the switch 72 tends to rotate anticlockwise, and thus to open the feeler circuit through the contacts 70, 71 and close a machine-stopping circuit through contacts 73, 74. Adjacent the magnet 69 is an armature 81 connected by a wire 82 and coupling 83 to a bellcrank 84 the detent of which normally engages an abutment 86 on the switch 72 and restrains it from movement under the influence of the springs 79, 80. The detent can be released manually by means of an extension 88 from the armature 81 and the switch can be reset by means of a link 89 depending from the lever 77. During normal running, the feeler circuits are broken between the contacts 50, 51 and the machine stopping circuit between the contacts 73, 74. When a fault develops in the fabric, the machine is stopped by means of the mechanically-operated stop-motion shown in Fig. 4. Should a yarn break or run loose, one pair of contacts 51 will be bridged by the corresponding contact piece 48, thereby completing a feeler circuit operating the corresponding indicator and energizing the magnet 69 to withdraw the detent 84 and permit the rotary switch 72 to rotate. In rotating, the switch breaks the feeler circuit at the contacts 70, 71 and completes the machine-stopping circuit through the contacts 73, 74. The magnet is thus energized to turn the stud 32 and release the lever 25, which in moving to stop the machine breaks the machinestopping circuit in another place to minimise waste of current. When the fault in the yarn supply has been remedied and the machine is restarted, the indicator, the switch 72 and the core 102 should be reset. The member 72 may be arranged to operate the lever 25 mechanically, and the stop-motion may be operated on the interruption of the circuits by suitably arranging the contacts.